Gyroscopic Instability of a Drop Trapped Inside an Inclined Circular Hydraulic Jump

International audienceA drop of moderate size deposited inside a circular hydraulic jump remains trapped at the shock front and does not coalesce with the liquid flowing across the jump. For a small inclination of the plate on which the liquid is impacting, the drop does not always stay at the lowest position and oscillates around it with a sometimes large amplitude, and a frequency that slightly decreases with flow rate. We suggest that this striking behavior is linked to a gyroscopic instability in which the drop tries to keep constant its angular momentum while sliding along the jump

16p11.2 600 kb Duplications confer risk for typical and atypical Rolandic epilepsy

Rolandic epilepsy (RE) is the most common idiopathic focal childhood epilepsy. Its molecular basis is largely unknown and a complex genetic etiology is assumed in the majority of affected individuals. The present study tested whether six large recurrent copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 previously associated with neurodevelopmental disorders also increase risk of RE. Our association analyses revealed a significant excess of the 600 kb genomic duplication at the 16p11.2 locus (chr16: 29.5-30.1 Mb) in 393 unrelated patients with typical (n = 339) and atypical (ARE; n = 54) RE compared with the prevalence in 65 046 European population controls (5/393 cases versus 32/65 046 controls; Fisher's exact test P = 2.83 × 10−6, odds ratio = 26.2, 95% confidence interval: 7.9-68.2). In contrast, the 16p11.2 duplication was not detected in 1738 European epilepsy patients with either temporal lobe epilepsy (n = 330) and genetic generalized epilepsies (n = 1408), suggesting a selective enrichment of the 16p11.2 duplication in idiopathic focal childhood epilepsies (Fisher's exact test P = 2.1 × 10−4). In a subsequent screen among children carrying the 16p11.2 600 kb rearrangement we identified three patients with RE-spectrum epilepsies in 117 duplication carriers (2.6%) but none in 202 carriers of the reciprocal deletion. Our results suggest that the 16p11.2 duplication represents a significant genetic risk factor for typical and atypical R

Case Series and DARS2 Variant Analysis in Early Severe Forms With Unexpected Presentations

Objective: Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is regarded a relatively mild leukodystrophy, diagnosed by characteristic long tract abnormalities on MRI and biallelic variants in DARS2, encoding mitochondrial aspartyl-tRNA synthetase (mtAspRS). DARS2 variants in LBSL are almost invariably compound heterozygous; in 95% of cases, 1 is a leaky splice site variant in intron 2. A few severely affected patients, still fulfilling the MRI criteria, have been described. We noticed highly unusual MRI presentations in 15 cases diagnosed by WES. We examined these cases to determine whether they represent consistent novel LBSL phenotypes. Methods: We reviewed clinical features, MRI abnormalities, and gene variants and investigated the variants' impact on mtAspRS structure and mitochondrial function. Results: We found 2 MRI phenotypes: early severe cerebral hypoplasia/atrophy (9 patients, group 1) and white matter abnormalities without long tract involvement (6 patients, group 2). With antenatal onset, microcephaly, and arrested development, group 1 patients were most severely affected. DARS2 variants were severer than for classic LBSL and severer for group 1 than group 2. All missense variants hit mtAspRS regions involved in tRNAAsp binding, aspartyl-adenosine-5'-monophosphate binding, and/or homodimerization. Missense variants expressed in the yeast DARS2 ortholog showed severely affected mitochondrial function. Conclusions: DARS2 variants are associated with highly heterogeneous phenotypes. New MRI presentations are profound cerebral hypoplasia/atrophy and white matter abnormalities without long tract involvement. Our findings have implications for diagnosis and understanding disease mechanisms, pointing at dominant neuronal/axonal involvement in severe cases. In line with this conclusion, activation of biallelic DARS2 null alleles in conditional transgenic mice leads to massive neuronal apoptosis

De novo variants in CACNA1E found in patients with intellectual disability, developmental regression and social cognition deficit but no seizures

Background De novo variants in the voltage-gated calcium channel subunit α1 E gene (CACNA1E) have been described as causative of epileptic encephalopathy with contractures, macrocephaly and dyskinesias. Methods Following the observation of an index patient with developmental delay and autism spectrum disorder (ASD) without seizures who had a de novo deleterious CACNA1E variant, we screened GeneMatcher for other individuals with CACNA1E variants and neurodevelopmental phenotypes without epilepsy. The spectrum of pathogenic CACNA1E variants was compared to the mutational landscape of variants in the gnomAD control population database. Results We identified seven unrelated individuals with intellectual disability, developmental regression and ASD-like behavioral profile, and notably without epilepsy, who had de novo heterozygous putatively pathogenic variants in CACNA1E. Age of onset of clinical manifestation, presence or absence of regression and degree of severity were variable, and no clear-cut genotype–phenotype association could be recognized. The analysis of disease-associated variants and their comparison to benign variants from the control population allowed for the identification of regions in the CACNA1E protein that seem to be intolerant to substitutions and thus more likely to harbor pathogenic variants. As in a few reported cases with CACNA1E variants and epilepsy, one patient showed a positive clinical behavioral response to topiramate, a specific calcium channel modulator. Limitations The significance of our study is limited by the absence of functional experiments of the effect of identified variants, the small sample size and the lack of systematic ASD assessment in all participants. Moreover, topiramate was given to one patient only and for a short period of time. Conclusions Our results indicate that CACNA1E variants may result in neurodevelopmental disorders without epilepsy and expand the mutational and phenotypic spectrum of this gene. CACNA1E deserves to be included in gene panels for non-specific developmental disorders, including ASD, and not limited to patients with seizures, to improve diagnostic recognition and explore the possible efficacy of topiramate

A note on the decomposability of inequality measures

International audienceWe propose a decomposition of inequality measures. By taking the example of the decomposition of income inequality by components, we show that this decomposition fits the definition of two elements: the sum of pure marginal contributions of income components and the sum of the pairwise interactions of all income components. This decomposition relies on the Shapley function and remains valid for a decomposition by subgroups and by components

Preoperative Vascular Imaging for Predicting Intraoperative Modification of Peripheral Arterial Cannulation during Minimally Invasive Mitral Valve Surgery

Objective Minimally invasive mitral valve surgery using peripheral cannulation for cardiopulmonary bypass (CBP) is increasingly prevalent. Although conceptually straightforward, peripheral CBP involves challenges and risks specific to this method of perfusion. The utility of preoperative vascular imaging in predicting these technical challenges and preventing vascular complications was studied. Methods We performed a retrospective analysis of 73 consecutive patients undergoing minimally invasive mitral valve surgery using femorofemoral CBP with intraluminal aortic occlusion balloon catheter. All patients underwent preoperative computed tomography angiogram or magnetic resonance angiography to study the iliofemoral axes. Results None of the patients operated with this technique was found to have arterial stenoses. Patients with a femoral artery diameter of less than 7.3 mm needed bilateral or side-graft arterial cannulation significantly more frequently than patients with larger femoral arteries (46.2% vs 9.1%, P = 0.001). There was a trend toward more frequent modification of arterial cannulation strategy in patients with body surface area less than 1.7 m2 compared with larger patients (body surface area, 1.7–2.0) (26.3% vs 8.3%, P = 0.07). Patients needing high CBP flow rate (&gt;5 L/min) were no more likely to need dual arterial cannulation (18.2% vs 19.1%, P = 0.68). No patient experienced a vascular complication. Conclusions This preliminary study suggests that preoperative vascular imaging and patient evaluation may predict difficulties with femoral cannulation and perfusion, which can lead to better preoperative planning and potentially prevent vascular complications. Further data will be accumulated and analyzed to confirm these findings. </jats:sec

Perturbations on a liquid curtain near break-up: wakes and free-edges

International audienceWe report experiments on liquid curtains falling between two vertical wires. The flow is mainly driven by gravity, so that the Weber number (We) (ratio of momentum flux to twice the surface tension) is close to zero at the top of the curtain and increases downstream, with the possible existence of a location where We equals 1 (which turns out to be a singular point in the sheet, in terms of waves propagation). In the present paper, we focus on the curtain response to localized perturbations, i.e., formation of either surface waves or free edges behind a thin needle touching the curtain, with a special emphasis to what happens near the break-up limit. We extract and compare the shapes of two kind of “wakes” left behind the obstacle: classical triangular wake of standing sinuous waves and stationary hole involving two free edges pinned on the needle. It is found that these two wakes are very similar for high enough We, but behave very differently when We reaches 1 from above; the sinuous wake disappears, while the “hole wake” still exists, and its shape becomes rounded. Below We=1⁠, the hole can either stay stable, oscillate or expand and break the curtain. We provide exact analytical expressions for stationary free-edges that compare very well with experiments

Économie des outre-mer français : une introduction

National audienceAlthough characterized by their geographic, demographic and institutional diversity, French overseas territories share common difficulties due to their size and their exposure to shocks, leading literature to focus on their economic vulnerabilities. These vulnerabilities are, first of all, inherited vulnerabilities resulting from structural factors in overseas economies, but also constructed vulnerabilities when they result from inappropriate political choices. This special issue devoted by the Revue and eacute;conomique to French overseas territories addresses both of these issues through seven contributions which, beyond identifying and evaluating the faced problems, strive to define possible solutions.Bien qu’ils se caractérisent par leur diversité géographique, démographique et institutionnelle, les territoires d’outre-mer français partagent, de par leur taille et leur exposition aux chocs, des difficultés qui poussent la littérature dédiée à se concentrer sur leurs vulnérabilités économiques. Il s’agit tout d’abord des vulnérabilités subies résultant des caractéristiques structurelles des économies ultramarines, mais également des vulnérabilités construites lorsqu’elles découlent de choix politiques inadaptés. Ce numéro spécial consacré par la Revue économique aux outre-mer français aborde l’une et l’autre de ces problématiques à travers sept contributions qui, au-delà d’identifier et d’évaluer les problèmes rencontrés, s’attachent à définir des pistes de solutions

Multiphysics modeling of adhesive interface with damage

International audienceIn the context of fuel-cladding interaction modelling in fast nuclear reactors, a multiphysics cohesive zone model of an adhesive interface with damage is proposed in this work. For the moment, only traction/compression behaviour can be described with this model. The effects of temperature, mechanical state, damage and chemical reactions are incorporated in adhesive links modelling. Thermal conductivity is affected by damage. In traction, we model elastic-brittle behaviour which depends on temperature and adhesive links. In compression, we model solid-solid contact